How is patent ownership initially determined?

The initial ownership of a patent depends on the filing date of the application. For applications filed on or after September 16, 2012, the MPEP states:

‘For applications filed on or after September 16, 2012, the original applicant is presumed to be the owner of the application for an original patent. See 37 CFR 3.73(a).’

For applications filed before September 16, 2012:

‘For applications filed before September 16, 2012, the ownership of the patent (or the application for the patent) initially vests in the named inventors of the invention of the patent.’

This distinction is important for determining the initial owner of a patent or patent application.